Dear All, We would like to inform you the following 2 articles have been published in behavioural brain research and marine mammal science. For PDF reprints, please contact Mai Sakai at mai@ori.u-tokyo.ac.jp. ---- Sakai, M., Hishii, T., Takeda, S. & Kohshima, S. 2006. Laterality of flipper rubbing behaviour in wild bottlenose dolphins (Tursiops aduncus): Caused by asymmetry of eye use? Behavioural Brain Research, 170(2), 204-210. http://dx.doi.org/10.1016/j.bbr.2006.02.018 Abstract To determine whether wild Indo-Pacific bottlenose dolphins (Tursiops aduncus) at Mikura Island, Japan, show asymmetry of eye or flipper use during a social behaviour, we investigated the laterality of flipper-to-body (F–B) rubbing, in which one dolphin (“rubber”) rubs the body of another (“rubbee”) with its flipper. We analysed 382 episodes of video-recorded F–B rubbings performed by identified individuals (N= 111 rubbers). F–B rubbing was conducted significantly more frequently with the left flipper than with the right flipper. The duration of F–B rubbings was also significantly longer with the left flipper than with the right flipper. Of 20 dolphins, nine individuals showed significant left-side bias as the rubber in this behaviour, whereas no dolphins showed significant right-side bias. The results indicate a population-level left-side bias of the rubber in F–B rubbing. An analysis of the swimming configurations during this behaviour suggests that the asymmetry in F–B rubbing was caused not only by the laterality of the rubber, but by a preference for use of the left eye in both dolphins during this behaviour. Dolphins used the left eye significantly more frequently than the right eye during the inquisitive behaviour, while they showed no significant bias in flipper use during the object-carrying behaviour. These facts also suggest that the asymmetry of F–B rubbing is caused by the preference for using the left eye. Significant left-side bias was observed only in F–B rubbings initiated by the rubbee, in which the rubbee determined its position during this behaviour. This suggests that this behavioural asymmetry was enhanced by the rubbees choosing the left side of the rubber to ensure better and longer rubs. ---- Sakai, M., Hishii, T., Takeda, S. & Kohshima, S. 2006. Flipper rubbing behaviors in wild bottlenose dolphins (Tursiops aduncus). Marine Mammal Science, 22(4), 966-978. http://www.blackwell-synergy.com/doi/abs/10.1111/j.1748-7692.2006.00082.x Abstract “Flipper rubbing” behavior was quantitatively analyzed in wild Indo-Pacific bottlenose dolphins (Tursiops aduncus) around Mikura Island, Tokyo, Japan. We observed two types of flipper rubbing: (1) F-B rubbing; one dolphin (Rubber) rubbed its flipper over various parts of a partner’s (Rubbee) body, and (2) F-F rubbing; both dolphins rubbed each other’s anterior flipper edge in alternating shifts. F-B rubbings tended to be initiated by the Rubbee and were terminated by the Rubber. The Rubbee often moved actively its body part that was in contact with the Rubber’s flipper, and assumed side-up, upside-down, or other postures while the Rubber remained horizontal in most cases. These facts suggest that the Rubbee engaged in F-B rubbing more actively than the Rubber, and might receive some benefit from the frictional contact during F-B rubbing. Dolphins often switched their roles as Rubber and Rubbee between episodes of flipper rubbing bout. Adults and subadults exchanged F-B rubbing and F-F rubbing most often with individuals of the same sex in the same age class. F-B rubbing was frequent in mother-and-calf dyads. Our results suggest that flipper rubbing is an affiliative behavior which could be a quantitative measure of social relationships among individuals of this species in future studies. ---- Mai SAKAI mai@ori.u-tokyo.ac.jp International Coastal Research Center, Ocean Research Institute, The University of Tokyo, 2-106-1 Akahama, Otsuchi, Iwate 028-1102, Japan phone:+81-193-42-5611, fax: +81-193-42-3715